Command Line Interface

4-178

4

Mirror Port Commands

This section describes how to mirror traffic from a source port to a target port.

port monitor

This command configures a mirror session. Use the no form to clear a mirror
session.
Syntax
port monitor interface [rx | tx]
no port monitor interface
interface - ethernet unit/port (source port)
-unit - Stack unit. (Range: 1)
-port - Port number. (Range: 1-26/50)
rx - Mirror received packets.
tx - Mirror transmitted packets.
both - Mirror both received and transmitted packets.
Default Setting
No mirror session is defined.
Command Mode
Interface Configuration (Ethernet, destination port)
Command Usage
You can mirror traffic from any source port to a destination port for real-time
analysis. You can then attach a logic analyzer or RMON probe to the
destination port and study the traffic crossing the source port in a completely
unobtrusive manner.
Set the destination port by specifying an Ethernet interface with the interface
configuration command, and then use the port monitor command to specify
the source of the traffic to mirror.
When mirroring traffic from a port, the mirror port and monitor port speeds
should match, otherwise traffic may be dropped from the monitor port.
You can create multiple mirror sessions, but all sessions must share the same
destination port.
Table 4-55 Mirror Port Commands
Command Function Mode Page
port monitor Configures a mirror session IC 4-178
show port monitor Shows the configuration for a mirror port PE 4-179